Effects Of Earthworms Research Articles

How do earthworms affect the pathway of sludge bio-stabilization via vermicomposting?

How do earthworms affect the pathway of sludge bio-stabilization via vermicomposting?

Effects of Nano-zero-valent Iron and Earthworms on Soil Physicochemical Properties and Microecology in Cadmium-Contaminated Soils

The capacity of nano-zero-valent iron (nZVI) and soil animals to remediate heavy metal–contaminated soil has been widely studied. However, the synergistic effect of soil animals and nZVI has not been thoroughly investigated. Here, we studied the combined effect of earthworms and nZVI on soil physicochemical properties and microecology during remediation of cadmium (Cd)–contaminated soil. The results showed that although amendment with nZVI reduced earthworm survival and biomass, the combination of nZVI and earthworms was effective at reducing the available Cd (ACd) content of soil and improving its quality. ACd most effectively reduced by 75.3% in the presence of earthworms under the 0.25% nZVI combination. Meanwhile, the combined action of earthworms and nZVI significantly improved soil properties and increased the diversity of soil microorganisms. In the earthworm-free system, nZVI reduced ACd by increasing soil pH and the abundance of Stenotrophobacter in Cd-contaminated soil, in addition to the co-precipitation and adsorption reported in previous studies. Correlation analysis revealed that the combination of nZVI and earthworms synergistically decreased ACd by decreasing soil OM and increasing the relative abundance of Opitutus and Gemmatta. Overall, our study indicates that the combination of nano-zero-valent iron and earthworms is a potential system for in situ remediation of Cd-contaminated soils and provides a deep understanding of the mechanisms involved in remediation.

Legacy effects of earthworms on soil microbial abundance, diversity, and community dynamics

Legacy effects of earthworms on soil microbial abundance, diversity, and community dynamics

New insights into vermiremediation of sewage sludge: The effect of earthworms on micropollutants and vice versa

New insights into vermiremediation of sewage sludge: The effect of earthworms on micropollutants and vice versa

Appropriateness of introducing earthworms into sustainable agriculture from the perspective of soil carbon emissions

Appropriateness of introducing earthworms into sustainable agriculture from the perspective of soil carbon emissions

Individual and combined effects of earthworms and Sphingobacterium sp. on soil organic C, N forms and enzyme activities in non-contaminated and Cd-contaminated soil

Individual and combined effects of earthworms and Sphingobacterium sp. on soil organic C, N forms and enzyme activities in non-contaminated and Cd-contaminated soil

Invasive earthworms modulate native plant trait expression and competition

Biological invasions have major impacts on a variety of ecosystems and threaten native biodiversity. Earthworms have been absent from northern parts of North America since the last ice age, but non‐native earthworms were recently introduced there and are now being spread by human activities. While past work has shown that plant communities in earthworm‐invaded areas change towards a lower diversity mainly dominated by grasses, the underlying mechanisms related to changes in the biotic interactions of the plants are not well understood. Here, we used a trait‐based approach to study the effect of earthworms on interspecific plant competition and aboveground herbivory. We conducted a microcosm experiment in a growth chamber with a full‐factorial design using three plant species native to northern North American deciduous forests, Poa palustris (grass), Symphyotrichum laeve (herb) and Vicia americana (legume), either growing in monoculture or in a mixture of three. These plant community treatments were crossed with earthworm (presence or absence) and herbivore (presence or absence) treatments. Eight out of the fourteen above‐ and belowground plant functional traits studied were significantly affected by earthworms, either by a general effect or in interaction with plant species identity, plant diversity level and/or herbivore presence. Earthworms increased the aboveground productivity and the number of inflorescences of the grass P. palustris. Further, earthworms and herbivores together affected root tissue density of P. palustris and the specific leaf area of V. americana. In this study, earthworm presence gave a competitive advantage to the grass species P. palustris by inducing changes in plant functional traits. Our results suggest that invasive earthworms can alter competitive and multitrophic interactions of plants, shedding light on some of the mechanisms behind invasive earthworm‐induced plant community changes in northern North America forests.

Soil structure shifts with earthworms under different organic fertilization in salt‐affected soils

Abstract Earthworm incubation combined with organic fertilization is promoted as an amended measure to improve soil properties in the ecological restoration of various degraded soils. However, the impacts of earthworms on the soil aggregate size under different organic fertilization in salt‐affected soils have not yet been fully revealed. This hinders our ability to develop policies by which to alleviate soil salinization. In this study, under mesocosm experiments, we investigate the effects of earthworm (Aporrectodea trapezoides) and organic fertilization on the soil aggregate size after 16 weeks of incubation. The soil treated with clover residues showed lower earthworm survival rates and biomass compared to that treated with sheep manure. However, the soil macropores and large macroaggregate were higher in the soils treated with clover residue when earthworms were present. In addition, earthworm burrowing activities form pathways toward food patches improve the characteristics of soil macropores, and the properties of the residue itself play a decisive role. Moreover, whether earthworms are present or not significantly influences the soil macroporosity, macropore number, and soil electrical conductivity. This demonstrates that earthworms exhibit a key feature of soil physical functioning in salt‐affected soil. In conclusion, we propose that the application of earthworms with organic residues in salt‐affected soils is a priority in producing and maintaining favorable soil structure.

Synergistic effects of earthworms and cow manure under reduced chemical fertilization modified microbial community structure to mitigate continuous cropping effects on Chinese flowering cabbage

The substitution of chemical fertilizers with organic fertilizers is a viable strategy to enhance crop yield and soil quality. In this study, the aim was to investigate the changes in soil microorganisms, soil chemical properties, and growth of Chinese flowering cabbage under different fertilization treatments involving earthworms and cow manure. Compared with the control (100% chemical fertilizer), CE (30% reduction in chemical fertilizer + earthworms) and CFE (30% reduction in chemical fertilizer + cow dung + earthworms) treatments at soil pH 8.14 and 8.07, respectively, and CFC (30% reduction in chemical fertilizer + cow manure) and CFE treatments increased soil organic matter (SOM), total nitrogen (TN), available nitrogen (AN), and available potassium (AK) contents. Earthworms and cow manure promoted the abundance of Bacillus and reduced that of the pathogens Plectosphaerella and Gibberella. The mantle test revealed that pH was not correlated with the microbial community. Random forest analysis verified that AN, SOM, and TN were important factors that jointly influenced bacterial and fungal diversity. Overall, the synergistic effect of earthworms and cow manure increased soil fertility and microbial diversity, thereby promoting the growth and development of Chinese flowering cabbage. This study enhanced the understanding of how bioregulation affects the growth and soil quality of Chinese flowering cabbage, and thus provided a guidance for the optimization of fertilization strategies to maximize the yield and quality of Chinese flowering cabbage while reducing environmental risks.

Eisenia fetida impact on cadmium availability and distribution in specific components of the earthworm drilosphere.

Although the potential of vermiremediation for restoring metal-contaminated soils is promising, the effects of earthworms on the availability of soil metals are still debatable. Most previous studies considered the soil as a "whole black box." Mobilization or immobilization of metals are affected by earthworm activities within drilosphere hotspots under different soil conditions, which has not been specifically studied. Therefore, an improved 2D terrarium was designed to study the impact of earthworm activities on cadmium (Cd) fate in the drilosphere hotspots (burrow wall soils, burrow casts, and surface casts) of different artificially spiked Cd treatments (CK: 0 mg kg-1; LM: 1 mg kg-1; and HM: 5 mg kg-1) with different organic amendments (2% and 10%). The results revealed that Cd increased earthworm activities with the highest cast production in HM and the highest burrow length in LM. Earthworms exhibited a stronger tendency to reduce total Cd concentration by 4.48-13.58% in casts of LM soils, while 3.37-5.22% in burrow walls under HM treatments. Overall, earthworms could increase the availability of Cd in casts under all conditions (55.46-121.01%). The organic amendments decreased the total Cd concentration and increased the availability of Cd in the disturbed soil. A higher amount of organic amendment significantly decreased total Cd concentration of the drilosphere by 1.16-5.83% in LM and HM treatments, while increasing DTPA-Cd concentrations in all components by 23.13-55.20 %, 14.63-35.11%, and 3.30-11.41% in CK, LM, and HM treatments, respectively, except for earthworm non-disturbed soil and no-earthworm soil in HM treatments. Redundancy analysis (RDA) revealed that the moisture, pH, and total carbon contents in soil are the main factors affecting Cd bioavailability. In this study, we decoded the "black box" of soil by making it relatively simple to better understand the effects and mechanisms of earthworm activities on soil metal availability and consequently provided comprehensive insights for using earthworms in soil vermiremediation.

Isotopic evidence for the effects of earthworm and straw amendment on root carbon uptake of upland rice and maize

Isotopic evidence for the effects of earthworm and straw amendment on root carbon uptake of upland rice and maize

Non-native earthworms increase the abundance and diet quality of a common woodland salamander in its northern range.

The online version contains supplementary material available at 10.1007/s10530-023-03168-3.

Earthworms neutralize the influence of components of particulate pollutants on soil extracellular enzymatic functions in subtropical forests.

Human activities are increasing the input of atmospheric particulate pollutants to forests. The components of particulate pollutants include inorganic anions, base cations and hydrocarbons. Continuous input of particulate pollutants may affect soil functioning in forests, but their effects may be modified by soil fauna. However, studies investigating how soil fauna affects the effects of particulate pollutants on soil functioning are lacking. Here, we investigated how earthworms and the particulate components interact in affecting soil enzymatic functions in a deciduous (Quercus variabilis) and a coniferous (Pinus massoniana) forest in southeast China. We manipulated the addition of nitrogen (N, ammonium nitrate), sodium (Na, sodium chloride) and polycyclic aromatic hydrocarbons (PAHs, five mixed PAHs) in field mesocosms with and without Eisenia fetida, an earthworm species colonizing forests in eastern China. After one year, N and Na addition increased, whereas PAHs decreased soil enzymatic functions, based on average Z scores of extracellular enzyme activities. Earthworms generally stabilized soil enzymatic functions via neutralizing the effects of N, Na and PAHs addition in the deciduous but not in the coniferous forest. Specifically, earthworms neutralized the effects of N and Na addition on soil pH and the effects of the addition of PAHs on soil microbial biomass. Further, both particulate components and earthworms changed the correlations among soil enzymatic and other ecosystem functions in the deciduous forest, but the effects depended on the type of particulate components. Generally, the effects of particulate components and earthworms on soil enzymatic functions were weaker in the coniferous than the deciduous forest. Overall, the results indicate that earthworms stabilize soil enzymatic functions in the deciduous but not the coniferous forest irrespective of the type of particulate components. This suggests that earthworms may neutralize the influence of atmospheric particulate pollutants on ecosystem functions, but the neutralization may be restricted to deciduous forests.

Effect of Biochar and Earthworms on Mineralization of Organic Matter in Top Soil and Deep Soil

Effect of Biochar and Earthworms on Mineralization of Organic Matter in Top Soil and Deep Soil

Synergistic Effects of Earthworms and Plants on Chromium Removal from Acidic and Alkaline Soils: Biological Responses and Implications.

Soil heavy metal pollution has become one of the major environmental issues of global concern and solving this problem is a major scientific and technological need for today's socio-economic development. Environmentally friendly bioremediation methods are currently the most commonly used for soil heavy metal pollution remediation. Via controlled experiments, the removal characteristics of chromium from contaminated soil were studied using earthworms (Eisenia fetida and Pheretima guillelmi) and plants (ryegrass and maize) at different chromium concentrations (15 mg/kg and 50 mg/kg) in acidic and alkaline soils. The effects of chromium contamination on biomass, chromium bioaccumulation, and earthworm gut microbial communities were also analyzed. The results showed that E. fetida had a relatively stronger ability to remove chromium from acidic and alkaline soil than P. guillelmi, and ryegrass had a significantly better ability to remove chromium from acidic and alkaline soil than maize. The combined use of E. fetida and ryegrass showed the best effect of removing chromium from contaminated soils, wih the highest removal rate (63.23%) in acidic soil at low Cr concentrations. After soil ingestion by earthworms, the content of stable chromium (residual and oxidizable forms) in the soil decreased significantly, while the content of active chromium (acid-extractable and reducible forms) increased significantly, thus promoting the enrichment of chromium in plants. The diversity in gut bacterial communities in earthworms decreased significantly following the ingestion of chromium-polluted soil, and their composition differences were significantly correlated with soil acidity and alkalinity. Bacillales, Chryseobacterium, and Citrobacter may have strong abilities to resist chromium and enhance chromium activity in acidic and alkaline soils. There was also a significant correlation between changes in enzyme activity in earthworms and their gut bacterial communities. The bacterial communities, including Pseudomonas and Verminephrobacter, were closely related to the bioavailability of chromium in soil and the degree of chromium stress in earthworms. This study provides insights into the differences in bioremediation for chromium-contaminated soils with different properties and its biological responses.

The combined effects of faba bean and endogeic earthworms on soil microbial activity in intercrops

The combined effects of faba bean and endogeic earthworms on soil microbial activity in intercrops

Arbuscular mycorrhizal fungi mitigate earthworm-induced N2O emissions from upland soil in a rice-rotated wheat farming system

Arbuscular mycorrhizal fungi mitigate earthworm-induced N2O emissions from upland soil in a rice-rotated wheat farming system

Earthworms restructure the distribution of extracellular antibiotics resistance genes of sludge by modifying the structure of extracellular polymeric substances during vermicomposting

Earthworms restructure the distribution of extracellular antibiotics resistance genes of sludge by modifying the structure of extracellular polymeric substances during vermicomposting

Earthworms and long-term straw management practices interactively affect soil carbon and nitrogen forms across soil depths

Earthworms and long-term straw management practices interactively affect soil carbon and nitrogen forms across soil depths

Effects of Earthworm, Straw, and Citric Acid on the Remediation of Zn, Pb, and Cd Contaminated Soil by Solanum photeinocarpum and Pterocypsela indica

Regulation of exogenous substances and intercropping are effective methods to improve the efficiency of phytoremediation of heavy metal contaminated soil. A pot experiment was used to study the effects of earthworms, straw, and citric acid on the remediation of Zn, Pb, and Cd contaminated soil by monocropping and intercropping of Solanum photeinocarpum and Pterocypsela indica. The results showed that the bioaccumulation factors (BCF) of earthworms for Zn, Pb, and Cd were 0.07-0.13, 0.10-0.26, and 5.64-15.52, respectively. The addition of straw in the soil increased the biomass of earthworms by 22.29%-223.87% but reduced the heavy metal concentrations by 8.15%-62.58%. Straw and citric acid showed passivation and activation effects, respectively, but earthworms had no significant effect on the available concentrations of heavy metals in the soil. Earthworms had no significant effect on the heavy metal concentrations of P. indica but reduced the heavy metal concentrations of S. photeinocarpum. Straw showed an inhibitory effect on the concentrations of heavy metals in P. indica but promoted the concentrations of Cd in S. photeinocarpum. Citric acid had no significant effect on the heavy metal concentrations in S. photeinocarpum but significantly increased the Pb concentrations in P. indica. Intercropping significantly reduced the soil available heavy metal concentrations and increased the heavy metal concentrations in plant roots; however, it had no significant effect on heavy metal concentrations in plant shoots. The total extraction amounts of Zn, Pb, and Cd by plants were mainly manifested as P. indica>intercropping>S. photeinocarpum. The addition of earthworms increased the total extraction amounts of Zn, Pb, and Cd by 12.49%, 35.89%, and 29.01%, respectively, and the addition of straw+earthworms increased the total extraction amounts of Pb by 87.21%. The results indicated that straw significantly promoted the growth of earthworms and reduced their accumulation of heavy metals, and the addition of earthworms alone or in combination with straw can effectively improve the remediation potential of P. indica of Zn, Pb, and Cd contaminated soil.